WASHINGTON - President Obama is impatient. Congress won't act on immigration, he says, and therefore he will. The White House is coy as to what the president will do. But the leaks point to an executive order essentially legalizing an enormous new class of illegal immigrants, perhaps up to 5 million people.

One doesn't usually respond to rumors. But this is an idea so bad and so persistently peddled by the White House that it has been pre-emptively criticized by such unusual suspects as (liberal) constitutional law professor Jonathan Turley, concerned about another usurpation of legislative power by the "uber presidency," and the Washington Post editorial page, which warned that such a move would "tear up the Constitution."

If this is a trial balloon, the time to shoot it down is now. The administration claims such an executive order would be a corrective to GOP inaction on the current immigration crisis - 57,000 unaccompanied minors, plus tens of thousands of families, crashing through and overwhelming the southern border.

This rationale is a fraud. First, the charge Republicans have done nothing is false. Last week, the House of Representatives passed legislation that deals reasonably with this immigrant wave. It changes a 2008 sex-trafficking law never intended for (and inadvertently inviting) mass migration - a change the president endorsed before caving to his left and flip-flopping. It also provides funds for emergency processing and assistance to the kids who are here.

Second, it's a non sequitur. Suspending deportation for millions of long-resident illegal immigrants has nothing to do with the current wave of newly arrived minors.

Third, and most fatal, it is unconstitutional. Don't believe me. Listen to Obama. He's made the case for years. As in: "I swore an oath to uphold the laws on the books. … Now, I know some people want me to bypass Congress and change the [immigration] laws on my own. … That's not how our Constitution is written" (July 25, 2011).

"This notion that somehow I can just change the laws unilaterally is just not true. … There are laws on the books that I have to enforce" (Sep. 28, 2011).

"If, in fact, I could solve all these problems without passing laws in Congress, then I would do so. But we're also a nation of laws" (Nov. 25, 2013).

Laws created by Congress, not executive fiat.

Moreover, Obama had control of both houses of Congress during his first two years in office - and did nothing about immigration. So why now?

Because he's facing a disastrous midterm election. An executive order so sweeping and lawless would be impeachment bait. It would provoke a constitutional crisis and stir impeachment talk, thus scrambling the electoral deck. As in 1998, it would likely backfire against the GOP and save Democrats from an otherwise certain sixth-year midterm shellacking.

Such a calculation - amnesty-by-fiat to court impeachment - is breathtakingly cynical. But clever. After all, there is no danger of impeachment succeeding. There will never be 67 votes in the Senate to convict. But talking it up is a political bonanza for Democrats, stirring up a listless and dispirited base.

Impeachment talk energizes Democrats and deflects attention from the real-life issues that are dragging them down - the economy, Obamacare, the failures of Obama's foreign policy. Everything, in other words, that has sunk Obama to 40 percent approval, the lowest ebb of his presidency.

There's an awful irony here. Obama entered our national consciousness with an electrifying 2004 speech calling for healing the nation's divisions and transcending narrow identities of race, religion, politics and ideology. Four years later, that promise made him president. Yet he is prepared to inflict on the nation a destructive, divisive, calculated violation of the constitutional order and national comity - for partisan advantage. For this president, who offered a politics of transcendence, this would constitute a betrayal of the highest order.

According to White House leaks, the executive order will be promulgated by summer's end. Time enough to reconsider. Don't do it, Mr. President.